Microcrystalline cellulose is a linear polysaccharide composed of β-1,4-glucosidic bonds. It is a free-flowing, extremely fine, short rod-shaped or powdery, porous particle obtained by hydrolyzing natural cellulose with dilute acid to its limit degree of polymerization (LODP). These particles form a white, odorless, tasteless crystalline powder, exhibiting wide-ranging applications in various fields.

　　I. Sources and Preparation of Microcrystalline Cellulose

　　Microcrystalline cellulose is primarily derived from natural cellulose sources such as wood, cotton, cotton linters, wheat straw, rice straw, reeds, flax, mulberry bark, paper mulberry bark, and sugarcane bagasse. Its preparation methods mainly include acid hydrolysis and microbial fermentation (enzymatic hydrolysis). Acid hydrolysis involves reacting cellulose raw materials with inorganic acids to partially depolymerize them, followed by washing, drying, and pulverization to obtain microcrystalline cellulose. Microbial fermentation utilizes enzymes to degrade cellulose raw materials under specific microbial conditions, yielding microcrystalline cellulose.

　　II. Properties of Microcrystalline Cellulose

　　Microcrystalline cellulose possesses several excellent properties, including good stability, flowability, water absorption, and film-forming ability. It maintains stable performance under various conditions and is not easily affected by temperature or humidity. Microcrystalline cellulose also exhibits good flowability, facilitating its use in manufacturing various products. Its water absorption properties provide a significant advantage in manufacturing products requiring absorbency. Furthermore, microcrystalline cellulose can form excellent films, enabling its use in products requiring film-forming capabilities.

　　III. Applications of Microcrystalline Cellulose

　　Pharmaceutical Field: Microcrystalline cellulose has wide-ranging applications in the pharmaceutical field, such as in the manufacturing of oral medications, injections, and capsules. It can serve as a disintegrant, stabilizing emulsifier, binder, and diluent, enhancing drug stability and solubility, thereby improving drug efficacy.

　　Food Industry: In the food industry, microcrystalline cellulose is used as a dietary fiber and an ideal health food additive. It maintains emulsion and foam stability, improves liquid stability, and can serve as a thickener and emulsifier in the manufacturing of dairy products, frozen foods, and meat products.

　　Cosmetics Industry: Microcrystalline cellulose also finds extensive use in the cosmetics industry. It is used in the manufacturing of sunscreen, skincare products, and shampoos as a thickener, stabilizer, and filler, improving the quality and stability of cosmetics.

　　IV. Conclusion

　　In summary, microcrystalline cellulose, as a multifunctional natural polymer compound, exhibits broad application prospects in various fields such as pharmaceuticals, food, and cosmetics. With continuous technological advancements and increasing demands for improved quality of life, the applications of microcrystalline cellulose will expand further, and market demand will continue to grow. Therefore, strengthening the research and development of microcrystalline cellulose is crucial for promoting the development of related industries and improving people's quality of life.